Biomass long body, composite long body, long molded article and method for manufacturing biomass long body

Abstract

To provide a biomass long body with high fiber orientation.SOLUTION: A biomass long body obtained by deforming plant-based materials through application of pressure to cause relative positional changes between fiber cells has a fiber orientation degree of 60% or more and less than 100%, as determined by fast Fourier transform (FFT) analysis of microscopic images, and a fiber orientation angle of 10 degrees or less relative to its longitudinal direction. By compressively deforming a composite long body in which the biomass long body is impregnated with resin, a long molded article with high mechanical strength can be obtained.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a continuous biomass body, a continuous composite body, a continuous molded product, and a method for producing a continuous biomass body, which are deformed by applying pressure to a plant material to cause changes in the relative positions of fiber cells, and the like. [Background technology]

[0002] In recent years, there has been a demand to reduce the use of fossil fuels from an environmental perspective, and plant-based materials have been attracting attention as an alternative to plastics, which are used to make various molded products. For example, Patent Document 1 discloses a molded product that utilizes slip deformation, in which pressure is applied to a plant-based material to apply shear force to the intercellular layers, thereby changing the relative positions of the cells. However, the method described in Patent Document 1 makes it difficult to align the fiber direction throughout the molded product.

[0003] Meanwhile, Patent Document 2 discloses a method for producing a molded product from a plant-based material with uniform mechanical properties by aligning the fiber direction throughout the molded product. Specifically, the method uses a mold having a pressing section with a flat inlet extending laterally relative to the pressing direction (punch direction) and a flat mold-forming space communicating with the pressing section via the inlet and extending laterally relative to the pressing direction. The plant-based material is placed in the pressing section so that the fiber direction is perpendicular to the extrusion direction on the same plane, and the plant-based material is placed in the pressing section so that the tangential grain of the plant-based material is pressed (pressed in the R direction) and so that the fiber direction is perpendicular to the flow direction. Pressure is applied to the plant-based material in the pressing section to develop fluidity, and the plant-based material is then sent into the mold-forming space to form a molded product (flat plate). The flat plate (molded product) in Patent Document 2 has fibers oriented perpendicular to the longitudinal direction.

[0004] Patent Document 3 also discloses a method for producing a plant-based molded product in which compressed cells are arranged along the longitudinal direction. Specifically, the method uses a mold having a material feed section with a flat inlet extending laterally relative to the pressing direction (punch direction) and a linear shape-fixing section that communicates with the material feed section via the inlet and extends laterally relative to the pressing direction. The method involves placing a plant-based material in the pressing section so that the tangential grain of the plant-based material is pressed (pressed in the R direction) and so that the fiber direction of the plant-based material is parallel to the flow direction of the inlet. Pressure is applied to the plant-based material in the pressing section to develop fluidity, and the plant-based material is then sent into the shape-fixing section to form a linear molded product. The linear molded product in Patent Document 3 has fibers oriented in the longitudinal direction.

[0005] Furthermore, Patent Document 4 discloses a wood material for flow molding that has been subjected to a delignification treatment. Patent Document 4 states that delignification (removal or decomposition) of the plant body reduces the degree of lignin condensation, resulting in a relaxed state within the cell walls. It also states that removing or decomposing a portion of the lignin from the plant body through delignification and increasing the lignin content to 20% by mass or more can increase the fluidity of the wood material. Patent Document 4 further states that, to achieve fluidity in the wood material, the lignin in the hydrated wood material must be heated to a temperature above its thermal softening temperature (approximately 70 to 90°C), which requires heating the wood material. Patent Document 4 also discloses a flat plate molded using the wood material for flow molding in the extrusion apparatus of Patent Document 2, with the mold heated to 170°C. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-36941 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-161932 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-15031 [Patent Document 4] WO2022 / 004796 Summary of the Invention [Problem to be solved by the invention]

[0007] In recent years, with the advancement of research into plant-derived materials, there has been a demand for molded articles with higher strength and rigidity. Although the molded articles in Patent Documents 2 to 4 take into consideration the orientation of fiber cells, further improvements are required. The present invention aims to provide a long biomass body with a high degree of fiber orientation, a composite long body and a long molded product using the same, and a method for producing the long biomass body. [Means for solving the problem]

[0008] Given the above circumstances, the present inventors believed that the frictional force generated between fiber cells significantly affects fiber orientation when plant-based materials are subjected to pressure to induce fluidity. They then discovered that impregnating delignified plant-based materials with a lubricant can further reduce the frictional force between fiber cells. They also found that fluidity is induced in plant-based materials even at relatively low temperatures. They also focused on the pressing direction of the plant-based material. It is generally known that pressing the end grain of a plant-based material (in the fiber direction (L)) causes the fibers to buckle or crush. However, the present inventors found that by using a plant-based material with improved fluidity under pressure, the fibers do not buckle when pressed against the end grain (L) of the plant-based material, and instead induces intercellular sliding deformation, allowing the fiber cells to flow in the flow direction. They then discovered that controlling the fluidity of plant-based materials in this way can further improve the degree of fiber orientation, leading to the completion of the present invention.

[0009] The long biomass body of the present invention is a long biomass body that has been deformed by applying pressure to a plant material to cause changes in the relative positions of fiber cells, and is characterized by a fiber orientation degree of 60% or more and less than 100% obtained by fast Fourier transform (FFT) analysis of a microscopic image. In the long biomass body of the present invention, the fiber orientation angle with respect to the longitudinal direction is preferably 10 degrees or less. The long biomass body of the present invention has a density of 0.2 g / cm 3 or more, 0.6 g / cm 3 The following is preferred:

[0010] The long composite body of the present invention is characterized in that any one of the long biomass bodies of the present invention is impregnated with a resin. The long molded article of the present invention is characterized by being obtained by compressively deforming the composite long body of the present invention.

[0011] A first aspect of the method for producing a long biomass body of the present invention is a method for producing a long biomass body using a mold having a pressing section and a mold forming space, and is characterized by including a step of subjecting a plant body to a delignification treatment and producing a plant-based material impregnated with a lubricant, and a step of applying pressure to the plant-based material with the pressing section, causing the plant-based material to develop fluidity, and sending the plant-based material through an inlet of the pressing section into the mold forming space to form a long body. In the first aspect of the method for producing a long biomass body of the present invention, pressure is preferably applied to the plant material in a direction at an angle of 45 degrees or less with respect to the fiber direction (L direction) of the plant material. A first aspect of the method for producing a long biomass body of the present invention preferably includes a step of enclosing the long body in a soft pipe, and a step of compressing the soft pipe in which the long body is enclosed with a jig in one direction at a cross section perpendicular to the longitudinal direction of the long body, while moving the jig in another direction perpendicular to the one direction.

[0012] A second aspect of the method for producing a long biomass body of the present invention is a method for producing a long biomass body using a mold having a pressing section and a mold forming space, and includes a step of producing a plant-based material by subjecting a plant body to a delignification treatment, and a step of applying pressure to the plant-based material in the pressing section, causing the plant-based material to develop fluidity, and sending the plant-based material through an inlet of the pressing section into the mold forming space to form a long body, characterized in that pressure is applied to the plant-based material in a direction within 45 degrees to the fiber direction (L direction) of the plant-based material. A second aspect of the method for producing a long biomass body of the present invention preferably includes a step of enclosing the long body in a soft pipe, and a step of compressing the soft pipe in which the long body is enclosed with a jig in one direction at a cross section perpendicular to the longitudinal direction of the long body, while moving the jig in another direction perpendicular to the one direction. [Effects of the Invention]

[0013] The long biomass body of the present invention has a high degree of fiber orientation, making it suitable as a material for long molded products with high mechanical strength as an alternative to plastics. In addition, it can be produced by an extrusion process, which makes it highly productive. [Brief explanation of the drawings]

[0014] [Figure 1] Figure 1a is a plan view showing an example of an extrusion device for producing a long biomass body of the present invention, Figure 1b is a cross-sectional view taken along line X1-X1, and Figure 1c is a partial cross-sectional schematic view showing the state in which a long biomass body is being extruded using the extrusion device. [Figure 2] 2a and 2b are cross-sectional schematic views showing the state in which the long molded article of the present invention is produced from the composite long body of the present invention. [Figure 3]Figure 3a is a cross-sectional view showing the state of a long biomass body inserted into a soft pipe, Figures 3b and 3c are schematic diagrams showing the state of the soft pipe of Figure 3a before and after being compressed with a smoothing jig, Figures 3d and 3e are schematic diagrams showing the state of the compressed soft pipe being homogenized with a smoothing jig, and Figure 3f is a schematic diagram showing the state of the homogenized long biomass body. [Figure 4] FIG. 4a is a reflection image of a long biomass body of the present invention, and FIG. 4b is a spectral intensity distribution map obtained from the divided image by fast Fourier transform (FFT). [Figure 5] Figure 5a shows the distribution of the intensity A and direction θ calculated from the spectral intensity distribution diagram in Figure 4b, plotted and the approximate curve calculated using the approximate formula, and Figure 5b is a graph showing the parameters obtained from the approximate curve. [Figure 6] 6a to 6e are reflection images of Examples 1 to 4 and Comparative Example 1, respectively. [Figure 7] 7a and 7b are graphs showing the relationship between the degree of fiber orientation and Young's modulus obtained from the examples, and graphs showing the relationship between Young's modulus and strength, respectively. [Figure 8] Figures 8a and 8c are images showing the long biomass body before and after it was inserted into a heat-shrinkable tube and homogenized with a smoothing jig, and Figures 8b and 8d are reflection images of a long molded product produced from a long biomass body that was not homogenized and a long molded product produced from a long biomass body that was homogenized, respectively. DETAILED DESCRIPTION OF THE INVENTION

[0015] First, the long biomass body of the present invention will be described based on an embodiment.

[0016] "Long biomass bodies" A long biomass body is a deformed product of applying pressure to a plant-based material, causing changes in the relative positions of fiber cells. Here, the term "long body" refers to a material that extends in one direction with a fixed external shape, including wires and flat plates. For example, in the case of wires, this refers to a material with an aspect ratio (length / diameter) of 2 or more. An example of a long biomass body is an extrusion molded body, as shown below, which is obtained by applying high pressure to a plant-based material placed in a pressure-resistant pressing section and extruding it from an inlet with a specified cross-sectional shape.

[0017] The extrusion device for producing a long biomass body is not particularly limited, but an example thereof is an extrusion device 1 as shown in Figures 1a and 1b, which includes a die 10 having a pressing section 11 and a die forming section 12, and a punch 20. The die section 10 has four die forming sections 12. The pressing part 11 has a cylindrical or prismatic space 11a, and an inlet (inflow passage) 11b at its lower end that communicates with the die forming part 12. The punch 20 is inserted into the space 11a. The inlet 11b is oriented perpendicular to the insertion direction (pressure direction X) of the punch 20 and extends radially outward (inflow direction Y) from the space 11a of the pressing part 11. The cross section of the inlet 11b is circular. Four inlets 11b are provided so that the space 11a communicates with each forming part 12, and the four inlets 11b are arranged at equal radial intervals. The mold forming section 12 has a cylindrical mold forming space 12a. The mold forming space 12a extends straight and has the same cross-sectional shape as the inlet 11b. The mold forming section 12 is composed of two half bodies. Therefore, the long biomass body formed in the mold forming section 12 is removed by opening the half bodies. That is, as shown in Figure 1c, plant material M is introduced into the space 11a of the pressing section 11 of this extrusion device 1, and the punch 20 is lowered to apply pressure to the plant material M so that relative positional changes occur between the fiber cells, and the plant material M is then flowed into the mold forming section 12 from the inlet 11b, thereby forming a biomass elongated body BL with a circular cross section.

[0018] The plant material used for the long biomass body is a plant body that has been subjected to a delignification treatment. Examples of plant bodies include sawn boards, veneers, and wood veneers of plant bodies having cell walls, such as wood from conifers such as cedar, cypress, and pine, and broad-leaved trees such as poplar, beech, oak, and birch; bamboo; hemp plants such as jute, kenaf, flax, hemp, ramie, and sisal; and herbaceous plants, or waste materials thereof, or chemically treated versions of these.

[0019] Examples of delignification treatments for plants include the conventionally known Klaudiz method, Wize method, kraft pulping, soda method, phenol pulping, organic acid pulping, organosolv pulping, ASAM method, and bleaching treatment. In particular, delignification treatments based on the Klaudiz method (see Takahide Sakaguchi et al., "Wood Chemistry," Bun'ei-do Publishing, 1985, pp. 69-70) are preferred. By performing delignification treatments in this manner, lignin in the cell walls can be removed while being replaced with water.

[0020] Furthermore, the plant material that has been delignified is preferably saturated with water, particularly by immersing it in an aqueous solution containing a lubricant. By saturating the plant material with water, the lignin can be maintained in a state in which it has been replaced with water or a lubricant, thereby reducing the frictional force generated between fiber cells. Therefore, even at temperatures lower than the thermal softening temperature of lignin in wood (e.g., 70°C or lower), applying pressure to the plant material can cause it to become fluid. The water or lubricant is removed by being extruded from the plant material by the pressure in the extrusion device 1 or by drying. In other words, the water or lubricant does not affect the physical properties of the biomass elongate body.

[0021] The plant material that has been delignified has a peak at 2850-2950 cm in the ATR spectrum (infrared absorption spectrum obtained by the ATR method) of the inside or surface of the material by infrared spectroscopy. -1 The absorption peak due to CH stretching vibration detected at 1480-1540 cm -1 The absorption peak is due to the skeletal vibration of the aromatic ring, detected at 2850-2950 cm -1The height of the absorption peak due to the CH stretching vibration detected in the 1480-1540 cm -1 The ratio (HB / HA) of the height of the absorption peak (HB) due to the skeletal vibration of the aromatic ring detected in the HB / HA spectrum to the height of the absorption peak due to the skeletal vibration of the aromatic ring detected in the HB / HA spectrum is 1.10 or less, preferably 0.5 or less, more preferably 0.3 or less, particularly preferably 0.2 or less, and most preferably 0.15 or less. The lower limit of HB / HA is preferably 0.00 or more. The height of each peak is determined by drawing tangents at both ends of the peak to form a baseline, dropping a perpendicular line from the apex of the peak to this baseline, determining the intersection with the baseline, and then measuring the length from this intersection to the apex of the peak. For details, this is based on the disclosure of International Publication WO2022 / 004796. The lignin content of plant-based material obtained by delignification treatment of a plant body, as measured by the acetyl bromide method, is 25% by mass or less, preferably 10% by mass or less, particularly preferably 5% by mass or less, and 0% by mass or more, preferably 1% by mass or more, particularly preferably 2% by mass or more. If the lignin content is greater than 25% by mass, it becomes difficult to obtain fluidity. On the other hand, if the lignin content is less than 5% by mass, particularly high fluidity is easily obtained. The acetyl bromide method is a technique in which powdered wood material is decomposed in an acetic acid solution of acetyl bromide and the amount of dissolved lignin is converted into ultraviolet absorbance (see K. Iiyama et al., "An improved acetyl bromide procedure for determining lignin in woods and wood pulps," Wood Science and Technology, 1988, 22: pp. 271-280).

[0022] The degree of fiber orientation of the long biomass bodies is 60% or more, preferably 65% ​​or more, particularly preferably 70% or more, and most preferably 75% or more, but less than 100%. The fiber orientation angle with respect to the longitudinal direction of the long biomass body is 10 degrees or less, preferably 8 degrees or less, particularly preferably 7 degrees or less, and most preferably 6 degrees or less. How to determine the fiber orientation degree and fiber orientation angle will be explained in the case of a long molded product.

[0023] The density of the long biomass body is 0.2 g / cm 3 or more, preferably 0.25 g / cm 3 More preferably, 0.3 g / cm 3 or more, and 1.0 g / cm 3 or less, preferably 0.9 g / cm 3 or less, more preferably 0.8 g / cm 3 or less, more preferably 0.7 g / cm 3 Below 0.6 g / cm, particularly preferably 3 Below 0.5 g / cm, most preferably 0.5 g / cm 3 The following is the result.

[0024] "Composite long body" The composite elongated body of the present invention is a long-length biomass body that has been deformed by applying pressure to a plant-based material to cause changes in the relative positions of fiber cells and then impregnated with a resin. The composite elongated body has substantially the same fiber orientation degree and fiber orientation angle as the biomass elongated body before being impregnated with the resin. The resin is not particularly limited and can be appropriately selected depending on the application of the composite elongated body, and may be either a thermoplastic resin or a thermosetting resin. Examples of thermoplastic resins include acrylic resins; polyolefins such as polyethylene and polypropylene; cyclic polyolefins; polyethylene glycol; polystyrene; polyvinyl chloride; polyvinylidene chloride; polyvinyl acetate; polytetrafluoroethylene; ABS resins; AS resins; polyamides such as nylon; polyacetal; polycarbonate; modified polyphenylene ether; polyester resins such as polybutylene terephthalate and polyethylene terephthalate; polyphenylene sulfide; polysulfone; polyethersulfone; amorphous polyarylate; liquid crystal polymers; polyether ether ketone; polyimide; polyamide imide, etc. Examples of thermosetting resins include phenolic resins, epoxy resins, unsaturated polyesters, urea resins, melamine resins, diallyl phthalate, silicon resins, vinyl ester resins, polyimides, polyurethanes, etc. When using a thermosetting resin, a curing agent can be used in combination. The weight gain (WPG) due to resin impregnation is 20% by mass or more, preferably 40% by mass or more, more preferably 50% by mass or more, and particularly preferably 55% by mass or more, and is 80% by mass or less, preferably 70% by mass or less. The resin can be injected into the long biomass body in any manner that does not substantially change the fiber orientation or fiber orientation angle. For example, a reduced pressure injection method can be used, in which the long biomass body is subjected to reduced pressure to remove air and other substances from the body, and then a resin solution is injected at a predetermined pressure. The resin may further contain a plasticizer, an antioxidant, an ultraviolet absorber, an antioxidant, a filler, an antibacterial agent, an antiseptic, an antistatic agent, and the like.

[0025] The composite long body has a fiber orientation degree and fiber orientation angle that are substantially the same as those of the biomass long body. That is, the composite long body has a fiber orientation degree of 60% or more, preferably 65% ​​or more, particularly preferably 70% or more, and most preferably 75% or more, but less than 100%. The fiber orientation angle relative to the longitudinal direction of the composite long body is 10 degrees or less, preferably 8 degrees or less, particularly preferably 7 degrees or less, and most preferably 6 degrees or less. The method for determining the fiber orientation degree and fiber orientation angle of a composite elongated body will also be explained using a long molded product.

[0026] "Long shaped molded product" The long molded article of the present invention is formed by compressing and deforming a composite long body. For example, a long molded article can be formed by compressing a composite long body obtained by impregnating a long biomass body with a thermosetting resin along the longitudinal direction and in a direction perpendicular to the longitudinal direction, and then heating the composite body while maintaining this state to cure the thermosetting resin. The cross section of the long molded product may be a circle, a rectangle, a triangle, a pentagon or more polygon. For example, a long molded product P having a rectangular cross section can be molded by preparing a compression mold 31 having a groove 31a with a rectangular cross section extending in one direction, filling the groove 31a with one or more composite long bodies CL, and compressing the composite long bodies CL under predetermined conditions while inserting a long punch 32 having substantially the same width as the groove 31a into the groove 31a from above the composite long bodies CL. If a thermosetting resin is used as the resin for the composite long body CL, the composite long body CL is heated in a compressed state to a curing temperature.

[0027] This long molded product maintains the same fiber orientation and fiber orientation angle as the biomass long body or composite long body. That is, the fiber orientation of the long molded product is 60% or more, preferably 65% ​​or more, particularly preferably 70% or more, and most preferably 75% or more, but less than 100%. The fiber orientation angle of the long molded product relative to the longitudinal direction is 10 degrees or less, preferably 8 degrees or less, particularly preferably 7 degrees or less, and most preferably 6 degrees or less.

[0028] The fiber orientation degree and fiber orientation angle of a long molded product can be obtained from 8-bit grayscale images of the surface or longitudinal section (inside the molded product) of the long molded product taken at a resolution of 5.3 μm × 5.3 μm. The microscopic images can be obtained using any of an optical microscope, electron microscope, atomic force microscope, ultrasonic microscope, X-ray microscope, or neutron microscope. Specifically, the image of the obtained 80 mm long molded product is divided into nine images of 1600 pixels x 1600 pixels, as shown in Figure 4a. Then, a fast Fourier transform (FFT) is performed on each image to obtain the spectral intensity distribution (I(r,θ)) (see Figure 4b). Here, r is the distance from the center of the image, and θ is the angle relative to the upward direction of the image. Then, for a given direction θ, the integrated spectral intensity A(θ) along the r direction is calculated using the following equation (1). The relationship between intensity A and the direction θ is then plotted (see Figure 5a). TIFF2025128856000002.tif18169Here, the integration ranges are r1 = 8 pixels and r2 = 80 pixels. The calculated values ​​of the integrated spectral intensities are fitted to the following approximate equation (2) (Fig. 5a) by the least squares method. TIFF2025128856000003.tif24151Note that B is the baseline, θ0 is the angle between the longitudinal direction and the fiber direction, and a and b are the intensity components in the fiber direction and the direction perpendicular to the fiber, respectively. Then, the degree of fiber orientation D was defined by the following equation (3). TIFF2025128856000004.tif13154 Here, 2θh is the full width at half maximum for the transformation A(θ)-B of equation (2) (Fig. 5b), and is expressed by the following equation (4). TIFF2025128856000005.tif13150And the fiber orientation angle θ d is defined as the absolute value of θ0 in equation (2). In this way, the degree of fiber orientation and the fiber orientation angle can be determined from the image of the long molded product.

[0029] The fiber orientation degree and fiber orientation angle of the composite elongated body and the elongated molded product produced from this elongated biomass body are substantially the same as those of the elongated biomass body, and therefore the fiber orientation degree and fiber orientation angle of the elongated biomass body can be determined substantially as those of the elongated molded product. On the other hand, the fiber orientation degree and fiber orientation angle of the long biomass and long composite bodies can be determined in the same way as with long molded products by obtaining microscopic images of the surface or longitudinal section (inside the molded body) of the long biomass and long composite bodies, respectively, and then performing a fast Fourier transform to obtain the spectral intensity distribution from the images.The spectral intensity distribution is then integrated to examine the azimuthal angle dependence of the intensity, and the relationship between intensity A and θ is plotted.This can then be fitted to the approximate equation (2) (Figure 5a), and the fiber orientation degree D can be calculated from equation (3), or the fiber orientation angle θd can be calculated as the absolute value of θ0.

[0030] The Young's modulus (GPa) of a long molded product measured by a three-point bending test based on the bending property test method in accordance with JIS K7171 (2022) is 13.0 GPa or more, preferably 14.0 GPa or more, more preferably 15.0 GPa or more, particularly preferably 15.5 GPa or more, and most preferably 16.0 GPa or more, and is 30 GPa or less. The deviation of the Young's modulus measured at any eight points on the long molded product is 2.0 or less, preferably 1.5 or less, particularly preferably 1.0 or less, and most preferably 0.8 or less. The bending strength (MPa) of the long molded product measured by a three-point bending test based on the bending property test method based on JIS K7171 (2022) is 100 MPa or more, preferably 120 MPa or more, more preferably 130 MPa or more, particularly preferably 140 MPa or more, and most preferably 150 MPa or more, and is 300 MPa or less. Furthermore, the deviation of the strength measured at any eight points on the long molded product is 25 or less, preferably 20 or less, particularly preferably 15 or less, and most preferably 10 or less.

[0031] Next, a method for producing a long biomass body of the present invention will be described.

[0032] "First embodiment of method for producing long biomass body" A first aspect of the method for producing a long biomass body of the present invention includes the steps of preparing a plant material that has been subjected to a delignification treatment and impregnated with a lubricant, and applying pressure to the prepared plant material to obtain an extrudate, drying the extrudate, and forming the long biomass body. The method may also include a step of homogenizing the entire long biomass body.

[0033] The step of preparing the plant material is a step of cutting the plant body to a predetermined size, subjecting the cut plant body to a delignification treatment, and impregnating the delignified plant body with a lubricant.

[0034] The plant body is not particularly limited as long as it is cut so as to be able to be inserted into the space 11a of the pressing part 11. Although it depends on the size of the pressing part 11, for example, it may be a rectangular parallelepiped with height x length x width of 15 mm x 28 mm x 28 mm. As mentioned above, delignification treatment of plant materials can be carried out using conventional methods such as the Klaudiz method, Wize method, kraft pulping, soda method, phenol pulping, organic acid pulping, organosolv pulping, ASAM method, and bleaching. In particular, delignification treatment is preferably carried out in accordance with the Klaudiz method (see Takahide Sakaguchi et al., "Wood Chemistry," Bun'ei-do Publishing, 1985, pp. 69-70). In this case, it is preferable to carry out the treatment so that the mass loss of the plant material is 5% or more, preferably 20% or more, and particularly preferably 25% or more, but not more than 30%. For example, delignification can be achieved by immersing the plant material in a 1-5% aqueous sodium chlorite solution for a predetermined period of time at a temperature of 40-50°C and a pH of 3-5. To ensure that the treatment solution quickly reaches the interior of the plant material and promotes the reaction, it is preferable to preheat the material, then infiltrate the treatment solution by vacuum injection, and then perform the delignification treatment. After the predetermined period of time, the plant material is immersed in room-temperature water to stop the delignification reaction, and washed by repeatedly injecting water under vacuum and leaving the material to stand.

[0035] The method for impregnating the delignified plant body with a lubricant is not particularly limited, and can be carried out by immersing the delignified plant body in an aqueous solution containing a lubricant for a predetermined period of time. For example, a diffusion method can be used in which the delignified plant body in a water-saturated state is immersed in an aqueous solution containing a lubricant and left for three days or more. Examples of water-soluble lubricants include pectin, guar gum, xanthan gum, tamarind gum, carrageenan, polyethylene glycol, propylene glycol, carboxymethylcellulose (CMC), and polyethylene oxide. Polyethylene oxide is particularly preferred as a lubricant, and examples include polyethylene oxides with an average molecular weight of 2 million or more, preferably 3 million or more, more preferably 4 million or more, particularly preferably 5 million or more, and most preferably 6 million or more. By using polyethylene oxide with an average molecular weight of 2 million or more, the amount impregnated into the plant-based material can be reduced. Polyethylene oxide with a molecular weight of 2 million or more is viscous before pressure is applied and acts as a lubricant for fibrous cells. When subjected to high pressure, it decomposes into low-molecular-weight molecules that flow along with the impregnated water, resulting in minimal impact on the biomass elongated body. The lubricant content in the aqueous solution is 0.1% by mass or more, preferably 0.5% by mass or more, particularly preferably 0.8% by mass or more, and 5% by mass or less, preferably 3% by mass or less, particularly preferably 2% by mass or less. If the content is less than 0.1% by mass, the friction between fiber cells cannot be sufficiently reduced. On the other hand, if the content is more than 5% by mass, the lubricant is likely to remain in the biomass elongate body.

[0036] The process of applying pressure to the prepared plant-based material to form a long biomass body is a process in which pressure is applied to the plant-based material M prepared in the pressing section 11 of the extrusion device 1 using a punch 20, as shown in Figure 1c, to cause it to become fluid and then send it into the mold forming space 12a through the inlet 11b of the pressing section 11. First, the plant material is placed into the pressing unit 11. In this step, the plant material is placed so that the fiber direction (orientation) of the plant material is at an angle of 45 degrees or less, preferably 20 degrees or less, more preferably 10 degrees or less, particularly preferably 5 degrees or less, and most preferably 3 degrees or less relative to the longitudinal direction of the rectangular parallelepiped space 11a of the pressing unit 11. For example, this can be achieved by cutting the plant body to prepare the plant material so that the fiber direction is at a predetermined angle relative to the height direction. The temperature of the mold in the pressing section 11 is set to 1 degree or higher, preferably above room temperature, and within 90 degrees, more preferably within 80 degrees, even more preferably within 70 degrees, particularly preferably within 60 degrees, and most preferably within 50 degrees. The maximum punch surface pressure of the punch depends on the shape and size of the die, but is, for example, 5 MPa or more, preferably 10 MPa or more, particularly preferably 15 MPa or more, and is 200 MPa or less, preferably 150 MPa or less, more preferably 100 MPa or less, particularly preferably 70 MPa or less, and most preferably 50 MPa or less.

[0037] The process of homogenizing the entire elongated biomass body includes the steps of enclosing the generated elongated biomass body in a soft pipe, compressing the soft pipe in which the elongated biomass body is enclosed in one direction using a jig, and moving the jig in another direction perpendicular to the one direction while maintaining the compressed state. The process of enclosing the long biomass body in a flexible pipe can be carried out, for example, by enclosing the long biomass body in a heat-shrinkable tube (for example, with a shrink temperature of 90°C), shrinking it, and closing both ends. Specifically, the long biomass body is inserted into the heat-shrinkable tube, water is injected under reduced pressure, and in this state, compressed to a predetermined height, the tube is placed in an underwater environment (in a hot bath) at 90°C or higher and 100°C or lower, and the tube shrinks. Then, both ends of the heat-shrinkable tube are closed. The soft pipe T with the long biomass body BL enclosed therein is compressed by sandwiching the soft pipe T between a pair of smoothing jigs 40a and 40b, as shown in Figures 3a and 3b. In particular, the soft pipe T is compressed until the height of the soft pipe T is 30% or more, preferably 35% or more, and particularly preferably 40% or more, and 70% or less, preferably 60% or less, and particularly preferably 50% or less, of the height of the soft pipe T immediately after the long biomass body BL is enclosed. The process of moving the tool in another direction perpendicular to one direction while maintaining the compressed state involves moving at least one of the smoothing tools 40a, 40b in the left-right direction perpendicular to the compression direction and perpendicular to the longitudinal direction of the long biomass body, as shown in Figure 3c. At this time, it is preferable to move the smoothing tools 40a, 40b back and forth from side to side (see Figures 3d and 3e). When smoothing the smoothing tools 40a, 40b back and forth, the number of times is at least one, preferably at least five, more preferably at least 10, and particularly preferably at least 20, but not more than 300, preferably not more than 200, and particularly preferably not more than 100. It is particularly preferable to move the smoothing tools 40a, 40b 10 to 50 times. When moving both smoothing tools 40a, 40b, the upper and lower smoothing tools 40a, 40b are moved in opposite directions. The smoothing jigs 40a and 40b are moved slowly so as not to cause turbulence in the plant material (elongated biomass objects BL) inside the soft pipe T. By compressing the soft pipe in this way and moving it in a rolling motion, compressive shear force can be applied perpendicular to the fibers by the microelements of the long biomass body, as shown in Figure 3f, and any gaps present in the long biomass body can be eliminated while maintaining the degree of fiber orientation.

[0038] "Second embodiment of the method for producing a long biomass body" A second aspect of the method for producing a long biomass body of the present invention includes the steps of preparing a delignified plant material and applying pressure to the prepared plant material so that the fiber direction and the pressure direction form a predetermined angle to form a long biomass body. It may also include the step of homogenizing the entire long biomass body.

[0039] The step of preparing a plant material is a step of cutting a plant body into pieces of a predetermined size and subjecting the cut plant body to a delignification treatment. The cutting of the plant body and the delignification treatment of the plant body are substantially the same as those in the first embodiment of the method for producing a long biomass body described above.

[0040] The process of applying pressure to the prepared plant material to form a long biomass body is a process in which pressure is applied to the plant material M prepared in the pressing section 11 using a punch 20 so that the fiber direction and the direction of the punch form a predetermined angle, causing the material to become fluid and being sent into the mold forming space 12a through the inlet 11b of the pressing section 11 (see Figure 1c). The fiber direction of the plant-based material and the direction of the punch (the longitudinal direction of the space 11a of the pressing portion 11) are set to within 45 degrees, preferably within 20 degrees, more preferably within 10 degrees, particularly preferably within 5 degrees, and most preferably within 3 degrees. The temperature of the mold in the pressing section 11 is set to 1 degree or higher, preferably above room temperature, and within 90 degrees, more preferably within 80 degrees, even more preferably within 70 degrees, particularly preferably within 60 degrees, and most preferably within 50 degrees. The maximum punch surface pressure of the punch depends on the shape and size of the die, but is, for example, 5 MPa or more, preferably 10 MPa or more, particularly preferably 15 MPa or more, and is 200 MPa or less, preferably 150 MPa or less, more preferably 100 MPa or less, particularly preferably 70 MPa or less, and most preferably 50 MPa or less. The step of homogenizing the entire long biomass body is substantially the same as that in the first embodiment of the method for producing a long biomass body described above.

[0041] "Method of manufacturing a long composite body" The long biomass body is impregnated with a resin so as not to change the fiber orientation or fiber orientation angle. For example, a reduced pressure impregnation method is used in which the long biomass body is subjected to reduced pressure to remove air and other impurities, and then a resin solution is injected at a predetermined pressure and the solvent is removed by drying. As mentioned above, the resin is not particularly limited, but a thermosetting resin is preferred, and a phenolic resin is most preferred. The weight gain (WPG) due to resin impregnation is 20% by mass or more, preferably 40% by mass or more, more preferably 50% by mass or more, and particularly preferably 55% by mass or more, and is 80% by mass or less, preferably 70% by mass or less.

[0042] "Method for manufacturing long molded products" Next, a method for producing a long molded product by compressively deforming the composite long body will be described. The elongated molded product can be obtained by compressing the composite elongated body along the longitudinal direction in a direction perpendicular to the longitudinal direction. 2, a mold 31 having a groove 31a extending in one direction is prepared, a composite elongated body CL is filled into the groove 31a, and a long punch 32 having substantially the same width as the groove 31a is inserted into the groove 31a from above the composite elongated body CL while compressing it under predetermined conditions. If a thermosetting resin is used as the resin for the composite elongated body, the composite elongated body is heated to a hardening temperature in the compressed state. [Example]

[0043] "Long biomass bodies" Long biomass bodies were produced under the following conditions.

[0044] "Example 1" The cedar was cut into rectangular specimens with dimensions of 15mm height x 28mm length x 28mm width, with the fibers aligned in the height direction. The rectangular specimen was immersed in a 2 wt% sodium chlorite solution at 45°C and pH 4.5 for 18 hours. The delignification reaction was then stopped by immersing the specimen in room temperature water. Room temperature water was then pumped under reduced pressure and the specimen was left for 30 minutes to an hour. This series of steps was repeated 5 to 6 times. This yielded a delignified, water-saturated rectangular specimen (Plant-based Material 1). The mass loss due to the delignification process was 28%. Three plant samples 1 were stacked in the height direction and filled into the space 11a of the pressing section 11 of the extrusion device 10 shown in Figure 1, which had an extrusion ratio (space area / inlet area) of 38. The mold temperature was set to 40°C, and the punch was extruded at a displacement speed of 0.2 mm / sec to produce a long biomass body of Example 1 having a length of 80 mm and a circular cross-sectional shape with a diameter of 3 mm. The maximum surface pressure of the punch at this time was 56 MPa.

[0045] "Example 2" Three of the plant samples 1 were stacked in the vertical direction and filled into the space 11a of the pressing section 11 of the extrusion device 10 shown in Figure 1, which had an extrusion ratio (space area / inlet area) of 38. The mold temperature was set to 40°C, and the punch was extruded at a displacement speed of 2.0 mm / sec. The extrudate was freeze-dried and then cut to produce a long biomass body of Example 3, 80 mm long and with a circular cross-sectional shape of 3 mm diameter. The maximum surface pressure of the punch was 26 MPa.

[0046] "Example 3" A water-saturated rectangular sample was prepared by the same process as in Example 1, and the water-saturated rectangular sample was immersed in an aqueous solution of Alkox E-300 (1% by mass) and left for 3 days to impregnate it with the lubricant, thereby preparing plant-based material 2. Three pieces of plant-based material 2 were stacked in the height direction and filled into the space 11a of the pressing section 11 of the extrusion device 10 shown in Figure 1, which had an extrusion ratio (space area / inlet area) of 38. The mold temperature was set to 40°C, and the punch was extruded at a displacement speed of 0.2 mm / sec. The extrudate was freeze-dried and then cut to produce a long biomass body of Example 3 having a circular cross-section with a diameter of 3 mm and a length of 80 mm. The maximum surface pressure of the punch at this time was 28 MPa.

[0047] Example 4 Three of the plant-based materials 2 were stacked vertically and filled into the space 11a of the pressing section 11 of the extrusion device 10 shown in Figure 1, which had an extrusion ratio (space area / inlet area) of 38. The mold temperature was set to 40°C, and the punch was extruded at a displacement speed of 2.0 mm / sec. The extrudate was freeze-dried and then cut to produce a long biomass body of Example 4 with a length of 80 mm and a circular cross-sectional shape with a diameter of 3 mm. The maximum surface pressure of the punch was 26 MPa.

[0048] "Comparative Example 1" The square sample was immersed in an aqueous solution of polyethylene oxide (1% by mass) and left for 3 days to be impregnated with the lubricant, thereby preparing a plant-based material 3. Three pieces of plant-based material 3 were stacked in the height direction and filled into the space 11a of the pressing section 11 of the extrusion device 10 shown in Figure 1, which had an extrusion ratio (space area / inlet area) of 38. The mold temperature was set to 120°C, and the punch was extruded at a displacement speed of 2.0 mm / sec. The extrudate was freeze-dried and then cut to produce a long biomass body of Comparative Example 1, 80 mm long and with a circular cross-sectional shape and a diameter of 3 mm. The maximum surface pressure of the punch at this time was 162 MPa.

[0049] Four long biomass bodies were prepared for each of Examples 1 to 4 and Comparative Example 1, and the average densities thereof are shown in Table 1. [Table 1]

[0050] The density of the continuous biomass body of the Examples was lower than that of the continuous biomass body of the Comparative Examples. This indicates that the continuous biomass body of the Examples was extruded without excessively compressing the fiber cells. In particular, the continuous biomass body of Comparative Example 1 was not delignified, and therefore could not be extruded without using a heated mold. Furthermore, the density of the elongated biomass body of Example 4, which was impregnated with a lubricant and had a high punch displacement speed, was further reduced. This is thought to be because by applying force to the plant material, which contains a highly viscous liquid within its cells, by increasing the punch speed, the lubricant is less likely to escape from the plant material during application of force, and the fluidity of the plant material is maintained at a high level.

[0051] "Composite long body" The long biomass bodies of Examples 1 to 5 and Comparative Examples 1 and 2 were immersed in a phenolic resin aqueous solution (PX-341, Aica Kogyo Co., Ltd.) with a solids concentration of 12 to 45 wt% while removing the air from the long biomass bodies under a reduced pressure of 7.5 mmHg absolute, and then the pressure was returned to atmospheric pressure, replacing the air inside the long biomass bodies with the phenolic resin aqueous solution. The solvent was then evaporated by freeze-drying, producing four composite long bodies each. The average weight gain (WPG) values ​​for each of the bodies due to resin impregnation are shown in Table 2 below.

[0052] [Table 2]

[0053] It was found that the long composite bodies of Examples 1 to 4 could be impregnated with more resin than the long composite body of Comparative Example 1. It was also found that density had a significant effect on resin impregnation.

[0054] Four composite elongated bodies of Examples 1 to 4 and Comparative Example 1 were loaded into the compression device shown in Fig. 2, which had grooves of 80 mm in length and 10 mm in width, and pressed with a compression punch at 100 MPa at 120°C (length 80 mm x width 10 mm x thickness 1 to 2 mm). In this state, the body was heated from 120°C to 160°C to thermally cure the phenolic resin, producing a elongated molded product.

[0055] "Measurement of fiber orientation and fiber orientation angle" Using the image synthesis mode of a digital microscope (VHX-8000, KEYENCE Co.), 10 mm × 80 mm overall reflected images of the long molded products of Examples 1 to 4 and Comparative Example 1 were captured at an image resolution of 5.3 μm × 5.3 μm to obtain 8-bit grayscale images. Figures 6a to 6c show the overall images of Examples 1 to 4 and Comparative Example 1, respectively. The resulting overall image was then divided into 1600 pixel x 1600 pixel images, which were then subjected to a discrete Fourier transform to obtain the spectral intensity distribution (I(r, θ)). Here, the image was divided into nine images. Figure 4b shows the spectral intensity distribution obtained by performing a fast Fourier transform (FFT) on one image from Example 1. Here, r is the distance from the center of the image, and θ is the angle formed with respect to the upward direction of the image. Then, for a given direction θ of this spectral intensity distribution, the integrated spectral intensity A(θ) along the r direction was calculated using the following equation (1). TIFF2025128856000008.tif18169Here, the integral ranges were set to r1 = 8 pixels and r2 = 80 pixels. Figure 5a shows the calculated values ​​of the integrated spectral intensity of the spectral intensity distribution map in Figure 4b plotted as a function of intensity A and direction θ. This plot was fitted with the following approximate equation (2) by the least squares method. TIFF2025128856000009.tif24151Note that B is the baseline, θ0 is the angle between the longitudinal direction and the fiber direction, and a and b are the intensity components in the fiber direction and the direction perpendicular to the fiber, respectively. These B, θ0, a and b are calculated. Then, the fiber orientation degree D was calculated using the following equation (3). TIFF2025128856000010.tif13154Here, 2θh is the full width at half maximum for the transformation A(θ)-B of equation (2) (Figure 5b), and is expressed by the following equation (4). TIFF2025128856000011.tif13150And the fiber orientation angle θ d was calculated as the absolute value of θ0 in equation (2). For each long molded product, the fiber orientation degree and fiber orientation angle were determined from the nine divided images, and the average values ​​were calculated. These are shown in Table 3.

[0056] "Mechanical properties" For the long molded products of Examples 1 to 4 and Comparative Example 1, the Young's modulus (GPa) and bending strength (MPa) were measured at eight arbitrary points using a three-point bending test based on the bending property testing method in accordance with JIS K7171 (2022), and the average values ​​were calculated. The fiber orientation degree, fiber orientation angle, Young's modulus and bending strength of each long molded product are shown in Table 3 below.

[0057] [Table 3]

[0058] The long molded products of Examples 1 to 4 exhibited a high degree of fiber orientation, and also exhibited high values ​​for strength and Young's modulus. These results indicate a positive correlation between the degree of fiber orientation and Young's modulus, as shown in Figures 7a and 7b, and a positive correlation between Young's modulus and strength. Since the degree of fiber orientation is a value obtained from an image of the outermost surface of the long molded product, it is an index derived from the texture of the molded product surface. However, since a positive correlation between the degree of fiber orientation and Young's modulus is shown in Figure 7, it is also considered to be a useful index for evaluating the degree of fiber orientation of the entire molded product. It was found that by producing a long molded product with such a high degree of fiber orientation, a long molded product with a high Young's modulus and bending strength could be obtained.

[0059] "Homogenization process for long biomass bodies" The elongated biomass object (diameter 3.0 mm, length 80 mm) of Example 4 was inserted into a polyolefin shrink tube (diameter 3.6 mm, length 120 mm), water was injected into it under reduced pressure, and the tube was compressed to a height of 1.5 mm. The tube was then placed in a warm bath at 90°C to 100°C to shrink the tube. The ends of the tube were then sealed with an iron, and the elongated biomass object was enclosed in the tube (see Figure 8a). The upper and lower smoothing jigs 40a and 40b were then moved back and forth 30 times each, slowly in opposite directions to prevent turbulence in the elongated biomass body inside the heat-shrinkable tube. In other words, the heat-shrinkable tube was moved in a rolling motion. Figure 8c shows an image after the smoothing jigs had been moved back and forth. Holes were drilled at both ends of the heat-shrinkable tube, and the elongated biomass body was then freeze-dried and removed from the heat-shrinkable tube. This is Example 6. In the same manner as in Examples 1 to 4, a composite elongated body and a long molded product were produced from the continuous biomass body of Example 6. In producing the composite elongated body, a phenolic resin aqueous solution (PX-341, Aica Kogyo Co., Ltd.) with a solids concentration of 10 wt% was used for the continuous biomass body of Example 6. The weight gain (WPG) due to resin impregnation was 60±11%. The reflected image is shown in Figure 8b. Figure 8d is a reflected image of a long molded product produced from the continuous biomass body of Example 4. Similarly, the degree of fiber orientation, fiber orientation, Young's modulus, and bending strength were measured. The results are shown in Table 4. A comparison was also made with Example 4.

[0060] [Table 4]

[0061] Homogenization treatment slightly decreased the average fiber orientation, Young's modulus, and bending strength, but it also reduced the deviation (variation) in Young's modulus and bending strength. Furthermore, the fiber orientation angle improved slightly. This means that homogenization treatment of long biomass bodies can produce homogeneous long molded products with high mechanical strength. This is thought to be because homogenization treatment of long biomass bodies eliminated the drawbacks while maintaining the fiber orientation to a certain extent. [Industrial Applicability]

[0062] It has been found that the long molded products formed from the long biomass bodies of the present invention have high mechanical strength and are suitable as a substitute for plastics. The long molded products of the present invention can be used as structural materials in various fields, such as the automotive industry, furniture, home appliances, and housing construction materials. They can also be used as construction materials and decorative materials, in addition to structural materials. [Explanation of symbols]

[0063] 1. Extrusion equipment 10. Mold 11 Pressing section 11a Pressurized space 11b Inlet 12 Mold forming section 12a Mold forming space 20 punches 31 Compression mold 31a Groove 32 Compression punch 40a, 40b Smoothing jig M Plant-based materials BL Biomass Long Body CL Composite Long Body P Long molded product T Soft Pipe

Claims

1. A biomass elongate body that is deformed by applying pressure to a plant material to cause a change in the relative positions of fiber cells, The degree of fiber orientation obtained by fast Fourier transform (FFT) analysis of a microscope image is 60% or more and less than 100%. Long biomass bodies.

2. The fiber orientation angle with respect to the longitudinal direction is 10 degrees or less. The long biomass body according to claim 1 .

3. Density is 0.2 g / cm ３ or more, and 0.6 g / cm ３ Below is the The long biomass body according to claim 1 .

4. The biomass elongated body according to any one of claims 1 to 3 is impregnated with a resin. Composite elongated body.

5. A long molded product obtained by compressing and deforming the composite long body according to claim 4.

6. A method for producing a long biomass body using a mold having a pressing part and a molding space, delignifying the plant material and producing a plant-based material impregnated with a lubricant; and applying pressure to the plant-based material with the pressing unit, causing the plant-based material to exhibit fluidity, and feeding the plant-based material into the mold-forming space through an inlet of the pressing unit to form a long body. A method for manufacturing a long biomass body.

7. Pressure is applied to the plant-based material in a direction within 45 degrees to the fiber direction (L direction) of the plant-based material. The method for producing a long biomass body according to claim 6.

8. a step of enclosing the elongated body in a soft pipe; a step of compressing the flexible pipe in which the elongated body is enclosed in one direction with a jig at a cross section perpendicular to the longitudinal direction of the elongated body, while moving the jig in another direction perpendicular to the one direction, The method for producing a long biomass body according to claim 6 or 7.

9. A method for producing a long biomass body using a mold having a pressing part and a molding space, A step of producing a plant material by subjecting a plant body to a delignification treatment; and applying pressure to the plant-based material with the pressing unit, causing the plant-based material to exhibit fluidity, and feeding the plant-based material into the mold-forming space through an inlet of the pressing unit to form a long body. Pressure is applied to the plant-based material in a direction within 45 degrees to the fiber direction (L direction) of the plant-based material. A method for manufacturing a long biomass body.

10. a step of enclosing the elongated body in a soft pipe; a step of compressing the flexible pipe in which the elongated body is enclosed in one direction with a jig at a cross section perpendicular to the longitudinal direction of the elongated body, while moving the jig in another direction perpendicular to the one direction, The method for producing a long biomass body according to claim 9.

Images